Therapeutic aerosol dispensing systems have been known for some time that, using metering dispensing systems, have dispersed small particles for inhalation into the lungs. Uniform doses are very much desired.
Because inhalation therapy is frequently required for patients who may have defective vision, or be old or feeble or hurried; so that administration needs to be accomplished under adverse conditions of illumination, or under time pressure by persons whose vision and motor control is impaired; it is desirable that a dispenser be simple to operate and preferably of such construction that the dispenser can be assembled in only one fashion.
Preferably all essential parts are fastened together so that essential pieces cannot be misplaced during use. For instance the patient may desire to use his dispenser during an asthma attack when his concentration and motor coordination is impaired. The patient may need to administer a drug for asthma treatment very rapidly once an attack occurs. It is highly desirable that the patient not be frustrated with a complex assembly operation to prepare a dispenser for administration.